15. Ali Bin Adlan Al-Nahawi, for example, developed an encryption method based on substitution. In this method, the order of the Arabic alphabet is shuffled, and the key or the determined order is exchanged beforehand using a poem that contains all the alphabets in its verses. An example of such a verse is:

صحَّ عندي وقتُ شغل بهمُ أخذُ فظِّ كثُّ زطِّ ضَد جَسِ